Definition

A sulfamate-substituted monosaccharide with anticonvulsant activity. Although the mechanism of action has not been fully elucidated, topiramate appears to antagonize kainate/AMPA subtype glutamate receptors, which results in stabilization of hyper-excited neural membranes, inhibition of repetitive neuronal firing, and a decrease in propagation of synaptic impulses, thus impeding seizure activity. In addition, this agent enhances chloride channels activated by the inhibitory neurotransmitter GABA. Kainate/AMPA subtype glutamate receptors are ligand-activated cation channels that mediate the fast component of excitatory postsynaptic currents in neurons of the central nervous system.